Snow thrower with self-restoring impeller



April 23, 1963 P. E. LA TENDRESSE 3,086,304

' SNOW THROWER WITH SELF-RESTORING IMPELLER Filed Feb. 27, 1961 5 Sheets-Sheet 1 Philip E. Lzflrzdresse y 90%, M

April 23, 1963 P. E. LA TENDRESSE 3,

SNOW THROWER WITH SELF-RESTORING IMPELLER Filed Feb. 27, 1961 5 Sheets-Sheet 2 Philip fiLaEndresse April 23, 1963 P. E. LA TENDRESSE 3,086,304

SNOW THROWER WITH SELF-RESTORING IMPELLER m A m F 6 w W 4 //////////////A Phi/1,1) LaTndre se 1 gm, MEL/2% United States Patent 3,086,304 SNOW THROWER WITH SELF-RESTORING IMPELLER Philip E. La Tendresse, Baraga, Mich. Filed Feb. 27, 1961, Ser. No. 91,721 3 Claims. (or. 37-43) While snow throwers operate normally, they do excellent work and have long been satisfactory. They have, however, been vulnerable to foreign objects. The greatest difficulty with foreign objects has been at the impeller. Referring especially to snow throwers having the impeller located between two conveyor screws feeding snow to the impeller, it is apparent that any foreign object entering either feed screw would be fed by it into the path of the impeller. Some objects, such as small boards or heavy tough sticks have tended to get caught between the im peller and the surrounding structure, usually the bottom plate of the scoop. Sometimes the impeller would jam, and the snow thrower would cease to operate until the operator, got out and removed the offending piece by hand, often with great difiiculty. Occasionally, the impeller or part of the driving equipment for it, would break. To alleviate more serious trouble, a fail-easy impeller has sometimes been used. This has not made trouble any less frequent, but has made repair easier.

According to the present invention, trouble from ordinary foreign objects, such as can pass through the throwing chute, is virtually eliminated. This is accomplished by hinging the outer part of the impeller plate so that it can swing to accommodate the foreign objects; and pro viding yieldable but self-restoring means for normally holding the hinged impeller plate in its operating position.

Preferably the heart of this means is a spring at the rotational rear of the impeller plate which presses it against stops at its operating position with enough force not to yield under ordinary operating conditions. This spring yields to a tough foreign object, but returns the plate when it has passed the foreign object.

Designation 0 f Figures FIGURE 41 is a front view of a snow thrower embodying this invention.

FIGURE 2 is a view on an enlarged scale showing the key features of this invention in full side view.

FIGURE 3 is a fragmentary sectional view taken approximately along the line 33 of FIG. 2.

FIGURE 4 is a view somewhat similar to FIG. 3 but showing the impeller in tripped position as a result of striking a piece of wood which has entered the snow thrower.

Background Description Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose; as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

The snow thrower of this invention may be conventional in many respects. There may be the usual scoop 11 in which a shaft 12 is driven by a chain and sprocket 13, the chain of course extending to a power takeoff device on the vehicle which pushes the snow thrower ahead of it. The shaft 12 carries oppositely pitched conveyor screws or feed screws 14 and 16, each of which preferably includes two helical blades, and is driven in a direction to thrust toward the center all of the snow which 3,086,304 Patented Apr. 23, 1963 enters the scoop 11. As the snow approaches the center snow where it is desired.

Novel Features of Impeller As previously stated the impeller normally functions as if it were a rigid plate, its position being that seen in In fact, a port-ion 21 of the impeller is rigid with the shaft 12. However, the main outer portion 22 is hinged to the rigid portion by hinge 23. It normally lies parallel to the rigid portion 21, as seen in FIG. 3. The only need for hinging the portion 22 is the fact that occasionally hard objects such as boards or heavy sticks of wood enter the scoop 11 with the snow. In the past this has caused the whole snow thrower to jam and stop operating, and sometimes has caused breakage.

According to the present invention, the hinged outer portion 22 0f the impeller can bend back to accommodate such hard objects. Many such objects, after being struck once, will pass through the chute 19 with the snow. When one is too large to do so, the hinged impeller portion 22 will repeatedly swing back to accommodate it and the noise, usually accompanied by decreased output, will advise the operatorof the condition so that he can stop the machine and remove the object, whereupon full service is restored immediately.

The hinged impeller portion 22 is urged to the position shown in FIG. 3, by a sturdy spring 26 which surrounds a slide rod 27. One end of the slide rod carries a rigidly fitted collar or head 28 which is pivotally carried on a bolt 29 extending through wings 31 welded to the hinged impeller plate 22. The other end of slide rod 27 slides through a collar 33 which is pivotally mounted between wings 34 welded to the shaft 12. A lubrication nipple 37 in the outer portion of collar 33 may communicate with a passage leading to the bore through collar 33 for lubricating slide rod 27 in collar 33.

The spring 26 is normally in partially compressed condition firmly pressing the impeller plate 22 againststop means which may comprise essentially the ends of the two feed screws '14 and 16, or of one of the helical blades of each.

A very simple form of binge 23 has been shown. It may comprise the usual interfitting tubelike members 39 and 41, one set carried by the hinged impeller plate 22 and the other part by the rigid impeller port-ion 21. A hinge pin 43 extends through the two sets as seen best in FIG. 2, but terminates short of the ends. This is maintained in place by a pair of small bolts 44, one at each end. As seen in FIG. 4, the tubular hinge sections may be welded to their respective members.

FIG. 4 also shows the impeller plate 22 swung back to accommodate a foreign object 46. By comparison with FIG. 3, it will be seen that in FIG. 4 the spring 26 is compressed and the slide rod 27 has moved upwardly through collar 33 by an amount corresponding to the swinging movement of the impeller plate 22. It will be observed that the impeller plate 22 can swing something like twice as far as shown in FIG. 4 so that it can accommodate itself to a much larger foreign object than the object 46 shown.

As soon as foreign object 46 has passed through or been removed, or as soon as the impeller plate 22 swings past it, spiing 26 returns plate 22 to its active or normal Q a) position shown in FIGS. 1 to 3. Conceivably this could be accomplished by centrifugal force alone, some other form of resiliently yieldable means (a spring detent for example) holding it there. However, the more positive spring return illustrated is much preferred, has been found satisfactory, and represents full use of the invention.

It is greatly preferred to use this invention with a plurality of impellers as shown so that in their normal position they balance each other. This makes the invention especially suitable for the common snow throwers having two helical blades on each screw.

One advantage of holding the impeller plate 22 in its normal position by resiliently yieldable means is to prevent noisy ehattering when operating under normal load. Hence spring 26 should be mildly compressed in that position.

I claim: 1. A snow throwing rotor including a pair of oppositely pitched feed screws, and an impeller between the feed screws, including a peripherally located plate disposed normally in an operating position generally radially of the rotor and hinged along its inner edge to the rotor to swing between the operating position, and a position rearwardly therefrom, that is, in the direction opposite to the direction of rotation causing the screws to feed toward the impeller, and a compression spring rearwardly of the plate normall holding it in operating position, but yieldable to allow the plate to swing rearwardly to accommodate a foreign object, and effective after the object has been passed to restore the plate to its operating position;

said rotor including stop means against which said plate is pressed by said spring.

2. A snow throwing rotor including a pair of oppositely pitched feed screws, and

an impeller between the feed screws, including a peripherally located plate disposed normally in an operating position generally radially of the rotor and hinged along its inner edge to the rotor to swing between the operating position, and a position rear- Wardly therefrom, that is, in the direction opposite to the direction of rotation causing the screws to feed toward the impeller, and

a compression spring assembly at the rear of the plate including a guide rod pivoted to the plate and slidingly engaging a guide member pivoted to the rotor, and a compression spring surrounding said rod and compressed to exert a steadying force between said guide member and said plate when said plate is in operating position to yieldably hold said plate in said position;

said rotor including stop means against which said plate is pressed by said spring.

3. A snow throwing rotor assembly including a pair of oppositely pitched feed screws, and

an impeller between the feed screws, including a peripherally located plate disposed normally in an operating position generally radially of the rotor and hinged along its inner edge to the rotor to swing between the operating position, and a position rearwardly therefrom, that is, in the direction opposite to the direction of rotation causing the screws to feed toward the impeller, and

resiliently yieldabe means normally holding the plate in its operating position;

said rotor assembly being constructed to cause said plate, after passing a foreign object which has swung it from its operating position, to return to its operating position.

References Cited in the file of this patent UNITED STATES PATENTS 2,200,623 James May '14, 1940 2,364,666 Seaman Dec. 12, 1944 2,911,737 VonArx Nov. 10, 1959 FOREIGN PATENTS 368,380 France Oct. 4, 1906 

1. A SNOW THROWING ROTOR INCLUDING A PAIR OF OPPOSITELY PITCHED FEED SCREWS, AND AN IMPELLER BETWEEN THE FEED SCREWS, INCLUDING A PERIPHERALLY LOCATED PLATE DISPOSED NORMALLY IN AN OPERATING POSITION GENERALLY RADIALLY OF THE ROTOR AND HINGED ALONG ITS INNER EDGE TO THE ROTOR TO SWING BETWEEN THE OPERATING POSITION, AND A POSITION REARWARDLY THEREFROM, THAT IS, IN THE DIRECTION OPPOSITE TO THE DIRECTION OF ROTATION CAUSING THE SCREWS TO FEED TOWARD THE IMPELLER, AND A COMPRESSION SPRING REARWARDLY OF THE PLATE NORMALLY 